Virgin Mobile USA Inc. announced today its new unlimited calling plan "Totally Unlimited," set to be available for $79.99 per month starting with July 1. The new offer replaces the company’s $99.99 monthly fee for 1000 minutes.

The carrier will charge an additional $10 for text-messaging and e-mail use, and even so, the charges will be cheaper than most of the other offers, which generally reach about $100.

One of the main hooks for the new offer is its prepaid system, which enables customers to use the service without signing any contract and also allows them to leave at any time. The offer presents people with another option in a market heavily crowded by the national carriers demanding a two-year contract from their subscribers.

Other companies such as Verizon Wireless and AT&T have registered a significant sales boost since the launch of their unlimited offers, and Virgin Mobile also hopes for its strategy to turn out successful and bring in new subscribers.

Sprint Nextel Corp., which has a contract with Virgin Mobile to allow the use of its network, also offers two unlimited plans, charging $99 for voice, e-mail, Web browsing, text messages and video and a slightly cheaper plan of $89 just for voice and message.

Virgin Mobile was launched in the United Kingdom in 1999 and it was the world’s first Mobile Virtual Network Operator, as the company does not have a network of its own and uses the existing networks of other carriers.

With its more than 5 million customers, it is known as one of the largest MVNOs in the United States and also operates in Australia, India, France, Canada and South Africa.